Method for making stop cocks



Nov. 30, 1937. E. E. FORRESTER METHOD FOR MAKING STOP COCKS Filed Aug. 10, 1936 2 Sheets-Sheet 1 INVENTOR. ffim lfifl f. FOP/P567679 BY M ATTORNEY Nov. 30, 1937. E. E. FORRESTER 2,100,438

METHOD FOR MAKING STOP COCKS Filed Aug. 10, 1936 2 Sheets-Shem. 2

waimlilll Y g7 INVENTOR.

BY 2 ATTORNEY.

Patented Nov. 30, 1937 UNITED STATES PATEN'i' oer-ice METHOD FOR MAKENG STOP 'oooKs Edward E. Forrester, Denver, 0010.; IreneFOrrester executrix of Edward ceased Application August 10, 1936, Serial No. 95,149

2 Claims. (ores-4571)- This invention relates to improvements in methods for making stop cock bodies from tubular brass stock and similar ductile material, by a combination of hydraulic and mechanical pres- Stop cocks, in connection with the manufacture of which the method will be explained, are manufactured and sold in large numbers, and

l the bodies are usually cast in sand molds. Brass i castings frequently have blow holes, and in practically every case, sand adheres to the surfaces of the castings so tenaciously that some remains after the tumbling operation to which they are subjected. The blow holes-spoil the castings for '5 the use for which they are intended, and result in a high percentage of spoilage. In many cases the blow holes are not discovered until the stop cocks have been finished, and the labor expended is therefore Wasted. 0 Stop cocks have a tapered opening for the reception of a correspondingly tapered plug, and

these openings must be reamed before the plug can be inserted. It often happens that particles of sand adhering to the surface of the casting get caught by a reamer tooth, and embeds itself therein, with the result that the opening, instead of being smooth, has one or more grooves cut by the sand.

The sand also nicks the teeth of the reamer 3 and the latter must therefore be reground before it can again be employed,

Castings are, moreover, weaker than cold forgings, and due to the objections pointed out, are subject to a high percentage of spoilage.

'35- It is 13116 p n pal object of this invention to provide a method by which bodies for stop cocks and other articles of a similar nature, can be formed from hollow brass tubing by means of steel dies, and a combination of direct mechani- 40 cal pressure and hydraulic pressure applied to the cold metal.

Another object is to provide a method by which a tubular ingot can be bulged outwardly by a combination of pressure directly applied to its 45 ends, and liquid pressure applied to its inside in such a way that the bulged portion will retain its original thickness, and can even be made thinner than the original wall thickness.

Another object of this invention is to provide 59 a method of making hollow bodies, such as stop cock bodies, having intersecting openings, without the use of piercing tools or heat. 7

A further object is to produce a stop cock body in which the material is highly condensed and 55 therefore absolutely free from openings through E. Forrester, de-

which fiuid'may pass, and which will be strong and tough.

The method, briefly described, consists in progressively changing the shape of a tubular. ingot of brass or other ductile material, by placing it in specially formed dies of steel, and simultane ously applying pressure to the ends of the ingot by means of plungers and subjecting theinterior to hydraulicpressure of sufiicient value to force the material outwardly against the sides of the die, whereby it will, assume ashape in exact conformity With the die and will always remain hol- The stop cocks and the method by which they are formed will now be described in detail, and for this purpose, reference will be had to the accompanylng drawings in which the different steps of the method have been illustrated, and in which V Figure 1 is a section through a bulging die,

showing the tubular billet from which the stop cock body is to be made,in' place therein;

Figure 2 shows the shape of the billet after the first step of the method;

Figure 3 shows the billet after it has nealed and subjected to a second and fi ing operation; 7

Figure 4 is a section taken on line ,44, Figure-5 and shows the billet, illustrated in Figure 3, in position to be acted on by opposed plungers to change the shape of the enlarged central portion;

Figure 5 is a section taken on line 5--5, Figside View of the billet after it has been subjected to a forming operation in the dies shown in Figures 4 and 5 Figure 7 is a top planview of the billet shown in Figure 6;

Figure 6 is a a section through the last'form'ing Figure 9 is a side elevation of t tion taken on linesignates the base I 2.10am

a1 hula 2 5,

, the reception of the upper end of the billet II).

Die ii is provided with a circular flange I3 having three or more radially spaced openings for the reception of the bolts I4, whose upper ends are threadedly connected with openings I5 in the flange I6 of the anvil I? that extends into 'opening 7 in plunger 6.

The upper surface of the flange lfi'seatsagainst" the under surfaceof the plunger. Springs I8surround the bolts I4 and normally hold the parts in the position shown in Figure 1. Die H is also provided with an opening I9, concentric with opening I2, and somewhat smallerin diameter than the opening in the billet iii. A plunger 29 is slidable in opening I9, and has its upper end secured in an opening 2| in the anvil Il. Plunger 2% fits the opening I9 veryclosely, so as to prevent leakage and when the, parts are in the position shown, the plunger 20 projects slightly into opening I2.' a i I V For the first expanding operation the tubular and cylindrical billet In is first positioned in opening 9 in the die 8, and filled with oil. The upper end is then inserted in opening I2 in die I I. The plunger 6 is now moved downwardly and compresses the springs I8 whioh'exert pressure forcing thebottom of hole I2 into sealing contact with the upper end of the tubular billet.

When the anvil I'I moves downwardly relative to the die 8, the plunger 20 is moved into the tubular member and displaces an equal volume of oil, thereby putting the oil under great pressure. When the anvil comes into contact with the upper end of the die I I, further movement of amount of this bulge for a given compression of the billet I8 depends on the diameter of the plunger 26. ,After the press plunger has moved a predetermined distance, the press is reversed and the billet iiLwhich has now attained the shape shown in Figure 2, is removed and annealed. Since the material will not stand to be expanded, in one operation, the amount neces-' sary, the billet is subjected to a second operation, after it has been annealed, and this 'gives itthe shape shown in Figure 3. V

The billet shown in Figure 3 is now placed between the dies 23 and 24 that have a recess shaped to receive it. Dies 23 and 24 have rectangular openings 23 in which the plungers 2? are mounted. The inner ends of the plungers are transversely concave, as indicated by numeral 28.

Theassembly shown in Figure 4 is now placed in a press and the plungers subjected to forces P that move them inwardly at the same speed,

and thereby change the circular bulged portion into a transversely elongated tapered portion 22a. The sides are also pressed inwardly as indicated at 29, so as to form the port openings,

The billet after it has attained the shape 7 V 2,100,438 or table of a press, preferably a hydraulic press,

shown in Figures 6 and 7, is then ready for the final forming operation and is placed in a cavity between the die blocks 39 and 3I, Figure 8. The central portion 22a occupies a correspondingly shaped recess, and the ends I9 extend into the hexagonal openings 32. The dies with the billet in place therein are placed on the table 5 of a hydraulic press, and forced toward it by the. action of the plunger 6.

Before thedie is put into the press the plungers .33 are put into position and the interior of the billet filled with oil. The plungers 33 have their inner ends provided with cylindrical plugs 34.

The press ispreferably constructed specially for this purpose and has two horizontal opposed and axially alined plungers 35 that can be moved toward each othernat the same speed and these engage the ends of plungers 33 and move them inwardly with a force sufficient to cause the metal to flow and fill the cavity in the die. The oil in the body is subjected to very high pressure, and ferces the metal outwardly at the same time that it is compressed endwise by the plungers, and'as a result, a hollow valve body is formed that corresponds in every particular to the shape of the cavity in the dies.

The press employed for making a three-quarter inch stop cock body is capable of exerting a pressure of seventy tons against the plungers 33 and this enormous pressure transmitted to'the metal of the body by the plungers and the oil, flows the metal and makes it conform to every detail of the cavity.

After the billet has been subjected to the last described forming operation it hasthe shape shown in Figures 9, l0 and 11 and is ready for the small amount of machining necessary to make it a stop cock body.

The end 36 is removed, as by a drill,after which the interior of the plug chamber is reamed by a tapered reamer. Since there is no sand or grit adhering to the surface of the plug chamber, the reamer cannot be damaged and the operation is quickly performed.

' The ports 31 are formed during the forming operation when the depressions 29 are formed. The ends '38 are reamed and threaded as shown in Figure 14. Y

The inner surface of the plug chamber is provided with a groove 39 whose Wall tapers upwardly, and which receives a spring ring 40.

The plug 4| can be made in any suitable way, but is preferably made in a die 42 like that shown in Figure 12. This die is provided with a cylindrical cavity 43 whose diameter corresponds to the maximum diameter of the finished plug. .A narrow recess 44 extends downwardly from the bottom of the cavity; A plunger 45 has its upper end fastened to the plunger 6 of a press and the parts are adjusted so that the plunger is axially alined with the opening 43. A billet of heated brass is now dropped into the cavity and the plunger moved inwardly into the recess, whereupon the hot brass assumes the shape shown in section in Figure 12, The part in the diametrical recess 44 forms the handle 46 of the plug.

Ports 4B are now cutin theplug wall, and the latter subjected to a forming action by means of a die 49 having a tapered opening 50. The size and the taper of the opening 50 is such that the plug will fit the opening in the body of the cock. This correspondence can be effected by employing the same reamer for the tapered opening in the body and for the opening 50 in the die.

The spring ring 40 rests on the shoulder on the outer end of the plug, and presses outwardly against the tapered side of the groove 39, which produces a resultant force tending to force the plug into the opening in the body.

Although other similar articles, such as, pipefittings, crosses and tees can be made by this method, it has been described in connection with the production of stop cock bodies as these present a difiicult problem, and have a shape that it is difiicult to make except by molding or by methods employing hot metal and piercing tools.

A reference to Figs. G'and 7 shows how the body at this stage resembles a cross and if the center piece 22a is reduced in length on one side the article will be a tee. It is therefore apparent that the method can be employed in the manufacture of pipe fittings as well as stop cock bodies.

Since this method subjects the material to very high pressures and stresses, the resultant product is dense and tough. The strength of the material inthe finished product is more than twice that of cast brass.

Since there are no blow holes, and since there is no sand to interfere with the operation of the reamer, there is practically no spoilage, and if any, it is due entirely to accident.

Attention is called in particular to the fact that in carrying out this method the metal is shaped or formed while cold, which simplifies the operation very much and produces'a tougher product than would be obtained if the metal were formed while hot.

Having described the invention, what is claimed as new is:-

1. The method of making a stop cock body from a tubular member of ductile metal comprising the steps of expanding a section of the tubular member at substantially its middle portion to produce a circular enlargement concentric with the member, subjecting the circular enlargement to deforming pressure on diametrically opposite points for changing the enlargement to a transversely extending tapered chamber substantially circuinterior of the member to a hydraulic pressure producing a stress beyond the elastic limit of the metal whereby the body will be expanded and forced against the inside of the cavity to assume the shape of the latter and whereby the inside of L the member will be given a shape conforming to the shape of the plugs.

2. The method of making a hollow body from a tubular member of ductile metaL comprising the steps of, expanding a section of the tubular member at a point between its ends to produce an enlargement, subjecting the enlargement to a deforming pressure for changing its shape, confining the member in'a die having a cavity of the size and shape of thefinished body desired, in-

serting into and against the ends of the member shape forming plugs, thereby subjecting the ends to a compressive pressure producing a stress beyond the elastic limit of the metal wherebythe body will be shortened, the wall thereof thickened and forced against the outside of the plugs, and simultaneously therewith subjecting the interior of the member to a hydraulic pressure producing a stress beyond the elastic limit of the metal,

whereby the body will be expanded and forced against the inside of the die cavity to assume the shape of the latter and whereby the innersurface of the member will be given a shape corresponding to the shape of the plugs.

EDWARD'E. FORRESTER. 1 

